Podcast Summary
Stars undergo transformations, not life and death: Despite our understanding of stars' evolution, much is still unknown and the universe continues to surprise us with its complexities.
While we have made significant strides in understanding the birth, life, and death of stars, it's important to remember that stars don't truly have a "life" or "death" in the way humans do. Instead, stars undergo transformations, morphing from one form into another. When we observe stars in the night sky, we can make educated guesses about their current state and future evolution based on their characteristics. However, there is still much we don't know, and the universe continues to surprise us with its vast complexities. Jackie Faherty, a senior scientist and senior education manager at the American Museum of Natural History, emphasized this point during a StarTalk episode, reminding us that our knowledge is always expanding.
Exploring the Universe's Secrets: What Happens to Planets When Stars Die?: Discoveries of planets orbiting white dwarfs prove that life can exist around stars in their later stages, emphasizing the importance of continued scientific exploration.
The universe, including stars and their planets, is full of mysteries yet to be unraveled. Vera Rubin, a renowned astronomer, emphasized that humans are still in the kindergarten stage of understanding the cosmos. Despite our advancements, there's so much more to learn. One intriguing question is what happens to planets when their stars die. Stars, like our Sun, can transform into white dwarfs or neutron stars, and surprisingly, planets can survive these transitions. We've discovered planets orbiting white dwarfs, proving that life can exist around stars in their later stages. Our solar system, with its eight planets, also holds these secrets. Even Pluto, though demoted to a dwarf planet, could potentially harbor life around a white dwarf in the future. This ongoing exploration of the cosmos underscores the importance of continued scientific inquiry.
The Sun's Death and Consuming Its Children: During the sun's death, it will expand and engulf inner planets, leaving potential habitable planets in the outer solar system. Our bodies are made of star elements, and the origins of heavier elements are linked to supernovas.
Our sun, during its death process, will expand and engulf inner solar system planets, including Earth. This is referred to as a white dwarf consuming its children. There is observational evidence of this phenomenon through white dwarfs, which have remnants of planets in their composition. Additionally, when the sun eventually dies, it will get hotter, making other planets in our solar system potentially habitable. The idea of outliving the sun and finding another star system to travel to is suggested. The concept of stardust, where our bodies are made of atoms from stars, is further explored through the Astronomer's Periodic Table, which highlights the origins of various elements. While hydrogen and helium are believed to come from the Big Bang, heavier elements require higher-level explosions, such as supernovas, for their formation.
The Origin of Elements: A Comprehensive and Accurate Explanation: The astronomers' periodic table provides a more accurate and comprehensive explanation of where elements come from, challenging simplified school textbook answers. New discoveries suggest elements are formed through various stellar processes, not just mining. Science education should incorporate this knowledge for a holistic understanding of the universe.
The way we understand the origin of elements on the periodic table has evolved significantly over time. Jennifer Johnson's astronomers' periodic table, which illustrates the processes that led to the formation of various elements, is a testament to this. This diagram, which can be found online, provides a more comprehensive and accurate explanation of where elements like gold, silver, and copper come from, compared to the simplified answers given in school textbooks. Furthermore, the latest scientific discoveries suggest that elements higher than iron on the periodic table are not solely formed through the process of digging them out of the Earth, but rather from various stellar processes such as supernova explosions, neutron star mergers, and the death of low-mass stars. Understanding these connections can help us feel more connected to the universe and its wonders. Jackie Faherty, an astrophysicist at the American Museum of Natural History, emphasizes the importance of incorporating this knowledge into science education, particularly in New York State's curriculum. By doing so, students would gain a more accurate and holistic understanding of the universe and the elements that make up our world. In essence, the astronomers' periodic table serves as a reminder that our understanding of the universe is ever-evolving, and that science education should keep up with the latest discoveries to provide students with the most accurate and comprehensive knowledge possible.
Brown dwarfs and stars: Labels can be misleading: Brown dwarfs are not failed stars but unique celestial objects, and black holes are not failed stars but evolved forms of massive stars.
Failure is a misleading label when it comes to celestial bodies like brown dwarfs and stars. Brown dwarfs, which are sometimes referred to as failed stars, are not failures but objects that exist between stars and planets, lacking the mass to ignite nuclear fusion. Jupiter, despite being the largest planet, is not a failed star as it doesn't meet the requirements to be considered a brown dwarf. Similarly, black holes are not failed stars but the evolved form of massive stars that undergo a supernova explosion. It's essential to avoid labeling celestial bodies negatively and instead appreciate their unique characteristics. During a weekly science coffee meeting, astronomers discuss and review the latest peer-reviewed papers, and one intriguing topic that came up was the possibility of zombie stars, which is a fascinating concept but not yet scientifically proven.
A Star's Life: From Birth to Death: Stars live for millions to billions of years, spending most in a stable phase called the main sequence, then becoming unstable and going through various stages before dying, leaving an impact in the universe.
Stars, much like living beings, have different lifespans and life cycles. Low mass stars, which are the most common in the galaxy and have lifetimes longer than the current age of the universe, are considered the beacons of the history of the galaxy. High mass stars, on the other hand, live fast and die young. The death sequence of a star, or its aging process, is a significant part of its life. Stars spend most of their lives in a stable phase called the main sequence, where they burn hydrogen and maintain a balance between gravity and pressure. When they start to use up their fuel and go off the main sequence, they become unstable and go through various stages before eventually dying. This process can take anywhere from millions to billions of years, depending on the mass of the star. So, in essence, the life of a star is not just about its birth and existence, but also its death and the impact it leaves behind in the universe.
Exploring the mysteries of star life cycles and the concept of 'zombie stars': Stars can't naturally come back to life, but with external assistance, 'zombie stars' can be revived, showcasing the complex and ever-evolving nature of the cosmos
The universe is full of fascinating phenomena when it comes to the life cycles of stars. During our discussion at Science Coffee, we explored various aspects of this, including the dangers of living at the center of a galaxy due to radiation and instability, as well as the concept of "zombie stars." These are evolved stars that can be revived through the influence of a companion star or external material. However, it's important to note that a star cannot naturally come back into a stellar state on its own. Instead, it requires external assistance. This idea of a star coming back to life with the help of a companion is an intriguing concept, reminiscent of the concept of zombies in popular culture. It's a reminder of the complex and ever-evolving nature of the cosmos. If you're interested in learning more about the mysteries of the universe, be sure to tune in to StarTalk for more cosmic queries. And don't forget to follow Nagin Farsad on Twitter @NaginFarsad and Jackie Faherty @jferty for more fascinating insights into the world around us.
Star's dying phase could make far-orbit planets habitable: During a star's dying phase, planets in outer reaches could have ingredients for life and become habitable, but star collisions are rare and unpredictable.
During the dying phase of a star, the habitable zone where liquid water can exist moves away from the star. This means that planets in the outer reaches of a solar system, such as Enceladus, Europa, and even Pluto, could potentially have the ingredients necessary for life if they already exist. However, it's important to note that splitting a star in half is not possible with current technology and is highly unlikely to occur naturally. Instead, when two stars collide, they don't typically split evenly and the outcome is unpredictable. The rarity of star collisions also makes this an unlikely scenario for the emergence of new habitable planets. Overall, the possibility of far-orbiting planets becoming inhabitable during a star's death cycle depends on the presence of the necessary ingredients for life and the star's proximity to the new habitable zone.
Stars merging and splitting: fascinating but with consequences: Stars can merge and form larger ones, but their behaviors aren't political. The sun's potential explosion would be catastrophic, while distant stars' supernovas pose a threat but not too close.
Stars can merge and form new, larger stars, but if we had the power to separate and redistribute their material, we could create smaller stars. However, the nearest star to us, the sun, is crucial for our existence, and its potential explosion would be catastrophic for Earth. Stars outside our immediate solar system, if they go supernova, can pose a threat, but only up to a certain distance. The concept of stars merging and splitting is intriguing, but it's essential to remember that stars are not partisan entities, and their behaviors don't align with political metaphors. Additionally, the discussion touched upon the concept of stable objects in the universe, such as stars, having enough mass to create new ones. Overall, the conversation explored the fascinating and complex nature of stellar evolution and the potential consequences of various stellar events.
Stars: Destructive Yet Essential for New Life and Growth: Stars, particularly supernovas, are destructive yet essential for new life and growth. Youngest stars near us are 2M years old, oldest can be 10B years old, formed from collapsing cores of giant molecular clouds.
Stars, particularly supernovas, play a dual role in the universe - they can be destructive but also essential for new life and growth. While it's important to maintain a safe distance from a supernova if you're a habitable world, they are beneficial for enriching the area around them and triggering star formation. The closest stars to us can vary greatly in age, with some being relatively young and others very old. The youngest stars near us are around 2,000,000 years old, while the oldest can be over 10,000,000,000 years old. The gravitational pull that brings elements together to form a star comes from the collapsing core of a giant molecular cloud. This core collapses under its own gravity, causing the cloud to heat up and eventually ignite nuclear fusion, leading to the birth of a new star.
The first stars formed from the inherent gravity of hydrogen atoms: The first stars formed from the collective gravity of hydrogen atoms, leading to the creation of heavier elements and the formation of nebulas, with potential involvement of dark matter.
The first stars formed from the gravitational collapse of hydrogen clouds. Gravity is not an external force acting upon these clouds, but rather an inherent property of the hydrogen atoms themselves. The collective gravity of these atoms pulls them together, leading to the formation of the first, unstable, mostly hydrogen stars. These stars were unstable and eventually exploded, leading to the creation of heavier elements and the formation of nebulas. Dark matter, which is primarily composed of the mysterious and still not fully understood force of gravity, may have played a role in the early universe and the formation of these first stars. Despite our best efforts to understand it, gravity remains a complex and confusing phenomenon in the realm of physics.